The invention relates to a rivet coupling device which can fasten an electrical connector to a circuit board by means of rivets.
The connection/fastening of a plurality of members by means of rivets is well-known. FIG. 8 shows a perspective view of a conventional rivet coupling device 300 as disclosed in Japanese Patent Application Kokai No. 6-277786.
This device 300 is used to fasten together a lever member 302 and a base member 304 with a rivet 306. The device 300 has a contact die 308 which supports the rivet 306 that extends through the members 302 and 304, and an insert main body 310 which deforms the rivet 306 by pressing the rivet 306 from above. During rivet installation, a tubular end part 312 at the tip of the insert main body 310 presses and deforms the tip 314 of the rivet 306, and a retaining member 318 which is driven by a spring 316 on the insert main body 310 presses and holds the members 302 and 304 in position.
However, in the case of the conventional rivet coupling device 300 disclosed in Japanese Patent Application Kokai No. 6-277786, the contact die 308 is fixed; accordingly, the deformation of the rivet tip will vary according to variations in the length of different rivets 306. As a result, there is a risk that the strength of the finished rivet will be insufficient to maintain the attachment of the members 302 and 304. Also, there is a risk that the finished rivet will be too short to allow relative movement between the members 302 and 304 where that is the intended case.
Furthermore, in cases where the members 302 and 304 are relatively large such that rivets are required in several places, if there is a gap between the members 302 and 304 and the contact die 308 is fixed, the upper member will be pressed and deformed by an amount corresponding to the gap. There is a risk that various problems will arise as a result of this deformation.
Furthermore, since rivet coupling is accomplished by the insert main body 310 acting directly on the contact die 308, inaccuracies occur in cases where there is a deviation in the positions of the members 302 and 304 being fastened. As a result, there is a possibility that the members 302 and 304 will be damaged, or that the coupling device 300 itself will be damaged.
The present invention was devised in light of the above points.
One object of the invention is to provide a rivet coupling device which performs highly reliable rivet attachments.
Another object of the invention is to provide a rivet coupling device which can perform rivet coupling without damage to the members being fastened.
Still another object of the invention is to provide a rivet coupling device which prevents damage to the device itself.
These objects are accomplished by a rivet coupling device for fastening an electrical connector to a substrate, wherein the electrical connector has spring terminals that elastically contact the substrate. The rivet coupling device has a supporting die that supports a head part on one end of a rivet, and a pressing die that is operable to deform an end portion on an other end of the rivet. The rivet coupling device is characterized in that the supporting die is carried on a cam plate which is operably connected to the pressing die by a link mechanism, wherein when the pressing die is moved toward the supporting die, the supporting die is driven by the cam plate toward the pressing die, whereby the end portion of the rivet is deformed and the spring terminals are compressed against the substrate.
According to one aspect, a movable carrying plate supports the electrical connector on a side opposite from the substrate.
According to another aspect, the link mechanism has a connecting part which separates when the carrying plate deviates from a specified position during rivet coupling.
In the rivet coupling device of the present invention, the supporting die is carried on a cam plate which is linked to the pressing die via a link so that the supporting die moves in linkage with the pressing die, and when the pressing die moves toward the supporting die, the supporting die is cam-driven by the cam plate so that the supporting die approaches the pressing die, thus causing the rivet to be deformed in a state in which the spring terminals of the electrical connector are compressed toward the board to which the electrical connector is attached. Accordingly, deformation of the board by pressing during the coupling work can be prevented. Thus, there is no danger that the printed wiring on the surface of the board will be broken. Furthermore, since the connector is pressed by both the pressing die and the supporting die, deformation or warping of the connector following molding can be corrected, so that appropriate coupling can be performed. Furthermore, coupling can be reliably performed regardless of any variation in the dimensions of the rivets, so that highly reliable fastening of the connector can be accomplished. In particular, in cases where a plurality of connectors are mounted, the board is expensive, and since coupling can be performed without wasting such expensive boards, the merit of the present invention in terms of cost is conspicuous.
Furthermore, the connector carrying plate of the rivet coupling device of the present invention is made movable, and the device is constructed so that the link has a connecting part that can be separated when the connector carrying plate deviates from a specified position. In such cases, inaccurate coupling can be prevented, and damage to the rivet coupling device can also be prevented.